Welcome to the SeeMeCNC Community

Just wondering if anyone has had experience w/ both a build fan mounted to the effector and a build fan clipped onto or standing off to the side of the bed and if one or the other gave best results? Also, if anyone is just satisfied w/ the results either way I'd appreciate the feedback. I primarily print PLA, but plan on printing ABS soon.

This is my bed fan:
http://forum.seemecnc.com/download/file ... &mode=view it's out of an old psu. I mounted it to loc line so I can orient it however I need it. I print ABS mostly.
I do think it helps with prints like the calibration pyramid. The "legs" of that print wouldn't cool fast enough for the next layer. I also printed a voronoi panther lady using it. IMO these "lattice" type prints benefit from using it. It's tricky though, I think on some part geometries it can induce stresses, causing de-lamination or bad curling and so on. As always, controlling temps is troublesome. I am going to add a pot to it so I can control it's speed, sometimes full on is too much.

I have thought about trying an effector mounted one, but I like keeping the weight of the effector to an absolute minimum. I haven't even added LED's and such. So I can't really speak to that.

I do use my bed fan at the end of a print to cool everything down. I've had parts pop off my glass just from the rapid cooling saves me the prying off step

Batteau62 wrote:I do use my bed fan at the end of a print to cool everything down. I've had parts pop off my glass just from the rapid cooling saves me the prying off step

That rapid cooling at the end of a print can be your demise, depending on infill ratio. You're cooling the outside much faster than the inside of the part, and this *will* create thermal stresses that could lead to a variety of bad things, including post-printing delamination and warpage. You'll probably be ok with low infills, the the higher you go the more mass there is to cool and to generate stresses.

My comments on the topic at hand: I've always been fond of effector mounted solutions (see my 40mm fan duct: http://www.thingiverse.com/thing:134185). The pair worked quite well. Direct airflow will sharpen your features without creating too many stresses throughout the rest of the part. For the same reason I describe above I've avoided bed fans, and also because the one or two times I did use one it was nearly impossible to get larger parts to keep from curling off of the build surface.


Edit: removed some off topic ramble.

I've been meaning to ask, and didn't see alot of discussion in the forums about it.

It appears to me (please correct me if I'm wrong) that a clip on (nozzle?) fan is only? useful when you print small parts, as it cools the plastic off more quickly to allow a more firm underlayer, allowing you to decrease the minimum layer time in kisslicer, to increase your print speeds.

I guess the other side of that, is that it's not necessary at all for larger prints, as each layer has > 20 seconds or more to cool.

Seems to be borne out by batteau's comments.

I tried another really neat shrouded 40mm plan from thingiverse, but it essentially wrapped around the whole tip, so it was impossible watch print and layer quality. I'll try edward's this weekend.

Batteau62 wrote:This is my bed fan:
I have thought about trying an effector mounted one, but I like keeping the weight of the effector to an absolute minimum. I haven't even added LED's and such. So I can't really speak to that.

LEDs and cooling fans on the hot end will have no noticeable impact on print quality. If you don't believe me, try grasping the effector while it's in motion. You'll find our NEMA 17 steppers are VERY strong. Whatever inertia you add with LEDs and fans will be overcome many times over. I saw a video a few days ago of someone using a Rostock (not a Max, but similar) to print clay, with a huge tube of the stuff mounted to the effector. It must have weighed at least a few pounds. That's on top of the extruder, which was also mounted there.

I have and do use both.
The only big difference I have seen was moving to a squirrel cage fan on the effector, they move an unbelievable amount of air for the size of the fan, and that really helps when printing PLA.

Thanks for the info Polygonhell,

How many squirrel cage fans do you have mounted to the effector and are they all plugged into the Fan 0 port on the Rambo?

inventabuild wrote:Thanks for the info Polygonhell,

How many squirrel cage fans do you have mounted to the effector and are they all plugged into the Fan 0 port on the Rambo?

I just have the one currently, I actually have 3 of them, but 1 moves so much air I just haven't seen the point of connecting the others. Fan 0 has more than enough power to plug 3 fans in if that's what you want.

Great, thanks.

Polygonhell wrote:

inventabuild wrote:Thanks for the info Polygonhell,

How many squirrel cage fans do you have mounted to the effector and are they all plugged into the Fan 0 port on the Rambo?

I just have the one currently, I actually have 3 of them, but 1 moves so much air I just haven't seen the point of connecting the others. Fan 0 has more than enough power to plug 3 fans in if that's what you want.

Like this?

Where'd you get yours? Enquiring minds want to know!

Ebay, this isn't the same auction, but they are similar
http://www.ebay.com/itm/3-pcs-Brushless ... 0389680237

Polygonhell wrote:Ebay, this isn't the same auction, but they are similar
http://www.ebay.com/itm/3-pcs-Brushless ... 0389680237

How is noise on these?

theverant wrote:

Polygonhell wrote:Ebay, this isn't the same auction, but they are similar
http://www.ebay.com/itm/3-pcs-Brushless ... 0389680237

How is noise on these?

It's a 50mm high rpm fan, and about average for that. other parts of my machine are louder.